Method and apparatus for indicating fault in flexible ethernet

ABSTRACT

The present subject matter relates to the field of communications technologies, and in particular, to a method and an apparatus for indicating a fault in flexible Ethernet. The method for indicating a fault includes: detecting whether a fault occurs in at least one physical layer entity included in a flexible Ethernet group; and when a fault occurs in the at least one physical layer entity, periodically sending a fault indication code block to a flexible Ethernet client corresponding to the at least one physical layer entity in which the fault occurs. Not all bandwidth of a downstream transmission path in the flexible Ethernet is occupied, and data transmission on a non-faulty channel in a same flexible Ethernet group is not affected, thereby reducing a quantity of affected flexible Ethernet clients.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2018/122933, filed on Dec. 22, 2018, which claims priority toChinese Patent Application No. 201711437572.6, filed on Dec. 26, 2017,The disclosures of the aforementioned applications are herebyincorporated by reference in their entireties.

TECHNICAL FIELD

The present subject matter relates to the communications field, and inparticular, to a method and an apparatus for indicating a fault inflexible Ethernet.

BACKGROUND

The standards organization optical internetworking forum (opticalinternet forum, OIF) publishes a flexible Ethernet (FlexE for short) 1.0implementation protocol based on a 100 G Ethernet standard, and providesfunctions such as rate aggregation, sub-rating, and channelization basedon time-division multiplexing (TDM) of Ethernet service.

The rate aggregation of the FlexE supports a plurality of low-ratephysical interfaces in jointly carrying a high-speed Ethernet servicedata flow, and the sub-rating and the channelization allow that oneEthernet physical interface concurrently carries a plurality of low-ratedata flows. A large number of network devices supporting an Ethernetphysical interface are deployed on an access network and a metropolitanarea network of a live network, a FlexE interface is compatible with astandard Ethernet and extends functions and flexibility of the Ethernet,thereby having a great market application prospect and development spacein a deterministic low-latency, high-bandwidth scenarios, such asfifth-generation mobile communications (5G) front haul and backhaulnetworks and data center interconnection.

In the FlexE, slots are divided through TDM, to implement hard isolationof bandwidth of a transmission channel. One service data flow may beallocated to one or more slots, to match services at various rates. Aflexible Ethernet group (FlexE Group) may include one or more physicallink interfaces, and a slot allocation table corresponding to the FlexEgroup is referred to as a FlexE calendar. A slot mapping tablecorresponding to a single physical link is referred to as a FlexEsub-calendar (sub-calendar).

The FlexE calendar includes one or more sub-calendars. Each sub-calendarindicates how 20 slots are allocated to a corresponding flexibleEthernet client (FlexE Client). The FlexE client represents a clientdata flow that is transmitted in a specified slot (one or more slots) onthe FlexE group, and one FlexE group may carry a plurality of FlexEclients.

When a link in a FlexE group and carrying data of a FlexE client isfaulty, an Ethernet local fault (LF) signal needs to be sent in adownstream direction of each FlexE client that is carried on the FlexEgroup. After a fault occurs in a FlexE group, an LF signal iscontinuously sent to each FlexE client carried on the faulty FlexEgroup, and the continuously transmitted LF signal occupies all bandwidthof downstream transmission paths of these FlexE clients.

SUMMARY

Embodiments of the present subject matter provide a method and anapparatus for indicating a fault in flexible Ethernet, a network device,and a storage medium.

According to a first aspect, an embodiment of the present subject matterprovides a method for indicating a fault. The method includes: detectingwhether a fault occurs in at least one physical layer entity included ina flexible Ethernet group; and when a fault occurs in the at least onephysical layer entity, periodically sending a fault indication codeblock to a flexible Ethernet client corresponding to the at least onephysical layer entity in which the fault occurs.

In the foregoing technical solution, when a fault occurs in a physicallayer entity, a fault indication code block is sent to the flexibleEthernet client corresponding to the at least one physical layer entityin which the fault occurs. Compared to a technical solution in the priorart in which a local fault signal is continuously sent to each flexibleEthernet client carried on a flexible Ethernet group immediately after afault occurs in a physical layer entity, in the technical solutionprovided in this embodiment of the present subject matter, the faultindication code block is sent to the flexible Ethernet clientcorresponding to the at least one physical layer entity in which thefault occurs. Therefore, not all bandwidth of a downstream transmissionpath in the flexible Ethernet is occupied, and data transmission on anon-faulty channel in the same flexible Ethernet group is not affected,thereby reducing a quantity of affected flexible Ethernet clients.

With reference to the first aspect, in a first possible implementation,the periodically sending a fault indication code block to a flexibleEthernet client corresponding to the at least one physical layer entityin which the fault occurs includes: sending an idle code block betweensuch fault indication code blocks in adjacent periods.

With reference to the first aspect, in a first possible implementation,the periodically sending a fault indication code block to a flexibleEthernet client corresponding to the at least one physical layer entityin which the fault occurs includes: when the fault is detected,consecutively sending a plurality of fault indication code blocks to theflexible Ethernet client corresponding to the at least one physicallayer entity in which the fault occurs, periodically sending the faultindication code block to the flexible Ethernet client corresponding tothe at least one physical layer entity in which the fault occurs, andsending an idle code block between such fault indication code blocks inadjacent periods.

With reference to the first aspect, in the foregoing possibleimplementation, the fault indication code block includes a control typefield and a fault identification field which is used to indicate that afault occurs in a physical layer entity.

With reference to the first aspect, in the foregoing possibleimplementation, the fault indication code block further includes a faulttype identification field, the fault type identification field is usedto indicate a fault type of the fault occurred in the at least onephysical layer entity, and the fault type includes: the physical layerentity loses a signal, the physical layer entity cannot lock a codeblock, the physical layer entity cannot lock an alignment code block,and a high bit error rate alarm is detected in the physical layerentity. Optionally, the fault type may alternatively be: an alarmindicating that a physical coding sublayer is in a fault state; aphysical layer entity/instance loses flexible Ethernet group frame lockor multiframe lock; physical layer entity/instance mapping tables,physical layer entity/instance numbers, or flexible Ethernet groupnumbers carried during frame lock or multiframe lock are inconsistent;or a receive clock skew between a plurality of physical layerentities/instances in a flexible Ethernet group is excessively large andexceeds a range allowed by a chip.

With reference to the first aspect, in the foregoing possibleimplementation, the fault indication code block is a service layer alarmindication code block, and the service layer alarm indication code blockis defined based on any field reserved in an IEEE 802.3 standardspecification for a standard Ethernet.

With reference to the first aspect, in the foregoing possibleimplementation, whether the fault in the at least one physical layerentity included in the flexible Ethernet group disappears is detected;and when the fault in the at least one physical layer entity disappears,the fault indication code block is stopped from being sent to theflexible Ethernet client corresponding to the at least one physicallayer entity in which the fault occurs.

According to a second aspect, an embodiment of the present subjectmatter provides a method for indicating a fault. The method includes:detecting whether a flexible Ethernet client signal includes a faultindication code block; and when a predetermined fault indication codeblock is detected, continuously sending a fault signal to a user-networkinterface corresponding to the flexible Ethernet client signal.

In the foregoing technical solution, the fault indication code block maybe detected, and a capability, of flexible Ethernet, of notifying a nodeoutside a network that a fault occurs in a physical layer entity in aflexible Ethernet group in the network is retained.

With reference to the second aspect, in the foregoing possibleimplementation, after the predetermined fault indication code block isdetected, the fault indication code block is continuously detected; andwhen no fault indication code block is detected, the fault signal isstopped from being sent to the user-network interface.

In the foregoing technical solution, if no fault indication code blockis detected, the fault signal is stopped from being sent, therebyquickly enabling the exchange functions of a flexible Ethernet clientand a user side to continue to exchange information.

With reference to the second aspect, in the foregoing possibleimplementation, the fault indication code block includes a control typefield and a fault identification field which is used to indicate that afault occurs in a physical layer entity.

With reference to the second aspect, in the foregoing possibleimplementation, the fault indication code block further includes a faulttype identification field, the fault type identification field is usedto indicate a fault type of the fault occurred in the at least onephysical layer entity, and the fault type includes: the physical layerentity loses a signal, the physical layer entity cannot lock a codeblock, the physical layer entity cannot lock an alignment code block,and a high bit error rate alarm is detected in the physical layerentity. Optionally, the fault type may alternatively be: an alarmindicating that a physical coding sublayer is in a fault state; aphysical layer entity/instance loses flexible Ethernet group frame lockor multiframe lock; physical layer entity/instance mapping tables,physical layer entity/instance numbers, or flexible Ethernet groupnumbers carried during frame lock or multiframe lock are inconsistent;or a receive clock skew between a plurality of physical layerentities/instances in a flexible Ethernet group is excessively large andexceeds a range allowed by a chip.

With reference to the second aspect, in the foregoing possibleimplementation, the fault indication code block is a service layer alarmindication code block, and the service layer alarm indication code blockis defined based on any field reserved in an IEEE 802.3 standardspecification for a standard Ethernet.

With reference to the second aspect, in the foregoing possibleimplementation, that a predetermined fault indication code block isdetected means that one fault indication code block is detected, faultindication code blocks whose quantity is greater than a preset thresholdare detected in a predetermined quantity of received code blocks, orfault indication code blocks whose quantity is greater than a presetthreshold are detected within a predetermined time. That no faultindication code block is detected means that no fault indication codeblock or fault indication code blocks whose quantity is less than thepreset threshold are detected in the predetermined quantity of receivedcode blocks, or no fault indication code block or fault indication codeblocks whose quantity is less than the preset threshold are detectedwithin the predetermined time.

With reference to the second aspect, in the foregoing possibleimplementation, the fault signal is any one of a local fault signal, amultiplex section alarm indication signal, an optical data unit alarmindication signal, and a common public radio frequency interface-invalidsynchronization control word signal.

According to a third aspect, an embodiment of the present subject matterprovides an apparatus for indicating a fault. The apparatus includes: adetection module, configured to detect whether a fault occurs in atleast one physical layer entity included in a flexible Ethernet group;and a sending module, configured to: when a fault occurs in the at leastone physical layer entity, periodically send a fault indication codeblock to a flexible Ethernet client corresponding to the at least onephysical layer entity in which the fault occurs.

In the foregoing technical solution, when a fault occurs in a physicallayer entity, a fault indication code block is sent to the flexibleEthernet client corresponding to the at least one physical layer entityin which the fault occurs. In other words, instead of a solution inwhich a local fault signal is continuously sent to each flexibleEthernet client carried on a flexible Ethernet group immediately after afault occurs in a physical layer entity, the fault indication code blockis sent to the flexible Ethernet client corresponding to the at leastone physical layer entity in which the fault occurs. Therefore, not allbandwidth of a downstream transmission path in the flexible Ethernet isoccupied, and data transmission carried on a non-faulty channel in thesame flexible Ethernet group is not affected, thereby reducing aquantity of affected flexible Ethernet clients.

With reference to the third aspect, in a first possible implementation,the periodically sending a fault indication code block to a flexibleEthernet client corresponding to the at least one physical layer entityin which the fault occurs includes: sending an idle code block betweensuch fault indication code blocks in adjacent periods.

With reference to the third aspect, in a first possible implementation,the periodically sending a fault indication code block to a flexibleEthernet client corresponding to the at least one physical layer entityin which the fault occurs includes: when the fault is detected,consecutively sending a plurality of fault indication code blocks to theflexible Ethernet client corresponding to the at least one physicallayer entity in which the fault occurs, periodically sending the faultindication code block to the flexible Ethernet client corresponding tothe at least one physical layer entity in which the fault occurs, andsending an idle code block between such fault indication code blocks inadjacent periods.

With reference to the third aspect, in the foregoing possibleimplementation, the fault indication code block includes a control typefield and a fault identification field which is used to indicate that afault occurs in a physical layer entity.

With reference to the third aspect, in the foregoing possibleimplementation, the fault indication code block further includes a faulttype identification field, the fault type identification field is usedto indicate a fault type of the fault occurred in the at least onephysical layer entity, and the fault type includes: the physical layerentity loses a signal, the physical layer entity cannot lock a codeblock, the physical layer entity cannot lock an alignment code block,and a high bit error rate alarm is detected in the physical layerentity. Optionally, the fault type may alternatively be: an alarmindicating that a physical coding sublayer is in a fault state; aphysical layer entity/instance loses flexible Ethernet group frame lockor multiframe lock; physical layer entity/instance mapping tables,physical layer entity/instance numbers, or flexible Ethernet groupnumbers carried during frame lock or multiframe lock are inconsistent;or a receive clock skew between a plurality of physical layerentities/instances in a flexible Ethernet group is excessively large andexceeds a range allowed by a chip.

With reference to the third aspect, in the foregoing possibleimplementation, the fault indication code block is a service layer alarmindication code block, and the service layer alarm indication code blockis defined based on any field reserved in an IEEE 802.3 standardspecification for a standard Ethernet.

With reference to the third aspect, in the foregoing possibleimplementation, the detection module is further configured to detectwhether the fault in the at least one physical layer entity included inthe flexible Ethernet group disappears. The sending module is furtherconfigured to: when the fault in the at least one physical layer entitydisappears, stop sending the fault indication code block to the flexibleEthernet client corresponding to the at least one physical layer entityin which the fault occurs.

In the foregoing technical solution, if the fault in the physical layerentity disappears, the fault indication code block is stopped from beingsent, to notify a downstream device that a link fault is rectified andthe link is restored to normal.

According to a fourth aspect, an embodiment of the present subjectmatter provides an apparatus for indicating a fault. The apparatusincludes: a detection module, configured to detect whether the flexibleEthernet client signal includes a fault indication code block; and asending module, configured to: when a predetermined fault indicationcode block is detected, continuously send a fault signal to auser-network interface corresponding to the flexible Ethernet clientsignal.

In the foregoing technical solution, the fault indication code block maybe detected, and a capability, of flexible Ethernet, of notifying a nodeoutside a network that a fault occurs in a physical layer entity in aflexible Ethernet group in the network is retained.

With reference to the fourth aspect, in the foregoing possibleimplementation, the detection module is further configured to: after thepredetermined fault indication code block is detected, continuouslydetect the fault indication code block. The sending module is furtherconfigured to: when no fault indication code block is detected by thedetection module, stop sending the fault signal to the user-networkinterface.

In the foregoing technical solution, if no fault indication code blockis detected, the fault signal is stopped from being sent, therebyquickly enabling the exchange functions of a flexible Ethernet clientand a user side to continue to exchange information.

With reference to the fourth aspect, in the foregoing possibleimplementation, the fault indication code block includes a control typefield and a fault identification field which is used to indicate that afault occurs in a physical layer entity.

With reference to the fourth aspect, in the foregoing possibleimplementation, the fault indication code block further includes a faulttype identification field, the fault type identification field is usedto indicate a fault type of the fault occurred in the at least onephysical layer entity, and the fault type includes: the physical layerentity loses a signal, the physical layer entity cannot lock a codeblock, the physical layer entity cannot lock an alignment code block,and a high bit error rate alarm is detected in the physical layerentity. Optionally, the fault type may alternatively be: an alarmindicating that a physical coding sublayer is in a fault state; aphysical layer entity/instance loses flexible Ethernet group frame lockor multiframe lock; physical layer entity/instance mapping tables,physical layer entity/instance numbers, or flexible Ethernet groupnumbers carried during frame lock or multiframe lock are inconsistent;or a receive clock skew between a plurality of physical layerentities/instances in a flexible Ethernet group is excessively large andexceeds a range allowed by a chip.

With reference to the fourth aspect, in the foregoing possibleimplementation, the fault indication code block is a service layer alarmindication code block, and the service layer alarm indication code blockis defined based on any field reserved in an IEEE 802.3 standardspecification for a standard Ethernet.

With reference to the fourth aspect, in the foregoing possibleimplementation, that a predetermined fault indication code block isdetected means that one fault indication code block is detected, faultindication code blocks whose quantity is greater than a preset thresholdare detected in a predetermined quantity of received code blocks, orfault indication code blocks whose quantity is greater than a presetthreshold are detected within a predetermined time. That no faultindication code block is detected means that no fault indication codeblock or fault indication code blocks whose quantity is less than thepreset threshold are detected in the predetermined quantity of receivedcode blocks, or no fault indication code block or fault indication codeblocks whose quantity is less than the preset threshold are detectedwithin the predetermined time.

With reference to the fourth aspect, in the foregoing possibleimplementation, the fault signal is any one of a local fault signal, amultiplex section alarm indication signal, an optical data unit alarmindication signal, and a common public radio frequency interface-invalidsynchronization control word signal.

According to a fifth aspect, an embodiment of the present subject matterprovides a network device, including the apparatus according to anypossible implementation of the third aspect and the apparatus accordingto any possible implementation of the fourth aspect.

According to a sixth aspect, an embodiment of the present subject matterprovides a network device, including the apparatus according to anypossible implementation of the third aspect.

According to a seventh aspect, an embodiment of the present subjectmatter provides a computer-readable storage medium. Thecomputer-readable storage medium stores an instruction, and theinstruction is executed by a computer to implement the method accordingto the foregoing aspects.

According to an eighth aspect, an embodiment of the present subjectmatter provides a computer program product including an instruction.When running on a computer, the computer program product enables thecomputer to perform the method according to the foregoing aspects.

According to a ninth aspect, an embodiment of the present subject matterprovides a computer program. When running on a computer, the computerprogram enables the computer to perform the method according to theforegoing aspects.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic application diagram of a signal transmissiondevice in FlexE according to an embodiment of the present subjectmatter;

FIG. 2 is a schematic structural diagram of a PE node according to anembodiment of the present subject matter;

FIG. 3 is a schematic structural diagram of a P node according to anembodiment of the present subject matter;

FIG. 4 is a schematic diagram of a FlexE group carrying a plurality ofFlexE clients according to an embodiment of the present subject matter;

FIG. 5 is a schematic diagram of mapping and multiplexing in FlexE basedon Nx100 G PHYs in OIF FlexE 1.0 according to an embodiment of thepresent subject matter;

FIG. 6 is a schematic diagram of de-mapping and de-multiplexing in FlexEbased on Nx100 G PHYs in OIF FlexE 1.0 according to an embodiment of thepresent subject matter;

FIG. 7 is a schematic diagram of mapping and multiplexing in FlexE basedon Mx100 G PHYs in OIF FlexE 2.0 according to an embodiment of thepresent subject matter;

FIG. 8 is a schematic diagram of mapping and multiplexing in FlexE basedon Mx200 G PHYs in OIF FlexE 2.0 according to an embodiment of thepresent subject matter;

FIG. 9 is a schematic diagram of mapping and multiplexing in FlexE basedon Mx400 G PHYs in OIF FlexE 2.0 according to an embodiment of thepresent subject matter;

FIG. 10 is a schematic diagram of slot allocation in a FlexE groupincluding four physical interfaces according to an embodiment of thepresent subject matter;

FIG. 11 is a flowchart of a method for indicating a fault according toan embodiment of the present subject matter;

FIG. 12 is a schematic diagram of an idle code block according to anembodiment of the present subject matter;

FIG. 13 is a schematic diagram of an example of an SLAI code blockaccording to an embodiment of the present subject matter;

FIG. 14 is a schematic diagram of another example of an SLAI code blockaccording to an embodiment of the present subject matter;

FIG. 15 is a schematic diagram of still another example of an SLAI codeblock according to an embodiment of the present subject matter;

FIG. 16 is a flowchart of a method for indicating a fault according toan embodiment of the present subject matter;

FIG. 17 is a schematic diagram of an LF code block according to anembodiment of the present subject matter;

FIG. 18A to FIG. 18D are schematic diagrams of an example showing that aPHY fault occurs according to an embodiment of the present subjectmatter;

FIG. 19A to FIG. 19D are schematic diagrams of detecting a PHY faultaccording to an embodiment of the present subject matter;

FIG. 20A to FIG. 20D are schematic diagrams of sending an SLAI codeblock according to an embodiment of the present subject matter;

FIG. 21A to FIG. 21D are schematic diagrams of sending an LF signalaccording to an embodiment of the present subject matter;

FIG. 22A to FIG. 22D are schematic diagrams showing that a PHY faultdisappears according to an embodiment of the present subject matter;

FIG. 23 is a schematic structural diagram of an apparatus for indicatinga fault according to an embodiment of the present subject matter;

FIG. 24 is a schematic structural diagram of another apparatus forindicating a fault according to an embodiment of the present subjectmatter; and

FIG. 25 is a schematic block diagram of a fault indication deviceaccording to an embodiment of the present subject matter.

DESCRIPTION OF EMBODIMENTS

The technical solutions in embodiments of the present subject matter areapplied to a multi-node network that is based on a FlexE technology.FIG. 1 is a schematic application diagram of a signal transmissiondevice in FlexE according to an embodiment of the present subjectmatter.

FIG. 1 shows a network including a provider edge (PE) node and aprovider (P) node. The PE node is a network device connected to a userat a network edge, and the PE node is equipped with a network-to-networkinterface (NNI) and a user-network interface (UNI). The P node is anetwork device in a network and is equipped with only an NNI. Both thePE node and the P node may be referred to as switching devices or switchdevices. The PE node in FIG. 1 is connected to customer equipmentthrough a standard Ethernet interface, and P nodes are connected to eachother through a FlexE interface.

However, the standard Ethernet interface herein is only an example.Alternatively, the PE node may be connected to a synchronous digitalhierarchy (SDH) network through an SDH interface, connected to anoptical transport network (OTN) network through an OTN interface,connected to a common public radio frequency interface (common publicradio interface, CPRI) network through a CPRI, or connected to anotheruser equipment through another user equipment interface.

FIG. 2 is a schematic structural diagram of a PE node according to anembodiment of the present subject matter. The PE node has a plurality oftransmission paths from UNIs such as a standard Ethernet interface, anSDH interface, an OTN interface, and a CPRI to a FlexE interface. Forsimplicity, the following uses the standard Ethernet interface as anexample for description. Devices in all transmission paths are the same.The standard Ethernet interface is connected to a physical layer entity(PHY), and a detector-server layer alarm indication (dSLAI) is connectedto both the PHY and a layer-1.5 internal switching unit. An end of aservice-server layer alarm indication (sSLAI) is connected to thelayer-1.5 internal switching unit. The other end of the sSLAI isconnected to the FlexE interface sequentially through a flexibleEthernet shim (FlexE Shim) and the PHY

The sSLAI/dSLAI is responsible for the generation and termination of aserver layer alarm indication (SLAI) code block in the FlexE network.The SLAI code block herein is an example of a fault indication codeblock, and the following uses the SLAI code block as an example fordescription.

In the PE node, when a signal is transmitted from the standard Ethernetinterface to the FlexE interface, the sSLAI detects whether there is aPHY fault. When a signal is transmitted from the FlexE interface to thestandard Ethernet interface, the dSLAI detects whether there is an SLAIcode block in a received signal stream.

The PHY specifically includes a physical medium dependent (PMD)sublayer, a physical medium attachment (PMA) sublayer, and a physicalcoding sublayer (PCS).

Layer 1.5 is a data transmission layer related to a FlexE protocol. TheFlexE shim is responsible for mutual conversion from a standard Ethernetdata flow to a FlexE slot data flow.

FIG. 3 is a schematic structural diagram of a P node according to anembodiment of the present subject matter. The P node is equipped withonly an NNI. A difference between the P node and the PE node lies inthat the P node has two sSLAIs, and each sSLAI is connected to the PHYvia a FlexE shim.

The technical solutions in the embodiments of the present subject mattermay be implemented on a network device that supports layer-1.5switching. Specifically, the network device is a switch device thatsupports the FlexE interface.

In terms of structure, the network device in the embodiments of thepresent subject matter may be a box switch or a chassis switch. A dSLAIfunction may be added to a user-network interface chip of the networkdevice, and an sSLAI function may be added to a network-to-networkinterface chip of the network device.

FIG. 4 is a schematic diagram of a FlexE group carrying a plurality ofFlexE clients. One FlexE group carries a plurality of FlexE clients. Inother words, the FlexE shim multiplexes and maps a plurality of FlexEclients to one FlexE group. In addition, the FlexE shim may de-map andde-multiplex a FlexE group, to restore a plurality of FlexE clients fromthe FlexE group.

FIG. 5 is a schematic diagram of mapping and multiplexing in FlexE basedon Nx100 G PHYs in OIF FlexE 1.0 according to an embodiment of thepresent subject matter. As shown in FIG. 5, in a client block area, anidle code block (IDLE code block) is inserted/deleted from data that isof a FlexE client a to a FlexE client z and that includes 64 B/66 Bencoded data, to implement clock synchronization in a FlexE block area.In addition, slot allocation is performed, by using a FlexE calendarcorresponding to the FlexE group, on a data code block for which clocksynchronization has been completed, and the data code block istransmitted by using each sub-calendar after an overhead (overhead)field is inserted by a control part. After being scrambled, a PCSchannel is allocated to and an AM (alignment marker) code block isinserted into transmission data, and the transmission data istransmitted in a physical layer sequentially through a PMA and a PMD.When a PHY fault occurs, a fault control block is generated and istransmitted downstream together with a transmission data signal.

FIG. 6 is a schematic diagram of de-mapping and de-multiplexing in FlexEbased on Nx100 G PHYs in OIF FlexE 1.0 according to an embodiment of thepresent subject matter. A de-mapping and de-multiplexing processperformed by the FlexE shim is basically in reverse order of a mappingand multiplexing process. The FlexE shim de-biases, de-interleaves,removes an AM code block from, and then de-scrambles input data througha PCS channel. De-scrambled transmission data from a PHY is transmittedby using each sub-calendar, overhead is extracted from the de-scrambledtransmission data, and then each FlexE client is restored from a FlexEcalendar. In this process, when a PHY fault occurs, a local fault (LF)signal is generated in a sublayer (sublayers) defined by the FlexE, tonotify a downstream device and a device outside the network that the PHYfault exists.

After evolving from version 1.0 to version 2.0, the OIF FlexE specifiesthat a 100 G PHY carries one FlexE instance (Instance), a 200 G PHYcarries two FlexE instances, and a 400 G PHY carries four FlexEinstances.

FIG. 7 is a schematic diagram of mapping and multiplexing in FlexE basedon Mx100 G PHYs in OIF FlexE 2.0 according to an embodiment of thepresent subject matter. FIG. 8 is a schematic diagram of mapping andmultiplexing in FlexE based on Mx200 G PHYs in OIF FlexE 2.0 accordingto an embodiment of the present subject matter. FIG. 9 is a schematicdiagram of mapping and multiplexing in FlexE based on Mx400 G PHYs inOIF FlexE 2.0 according to an embodiment of the present subject matter.Herein, in FIG. 7, M=N, and each 100 G PHY carries one FlexE instance.In FIG. 8, M=N/2, and each 200 G PHY carries two FlexE instances. Forexample, a 200 G PHY 1 carries FlexE #A and FlexE #A+1. In FIG. 9,M=N/4, and each 400 G PHY carries four FlexE instances. For example, a400 G PHY 1 carries FlexE #A, FlexE #A+1, FlexE #A+2, and FlexE #A+3.

Using FIG. 8 as an example, a 200 G PHY carries two FlexE instances,namely, FlexE #A and FlexE #A+1. In FIG. 8, in a client block area, anidle code block is inserted/deleted from 66 B encoded data of FlexEclients a, . . . , and z, to implement clock synchronization in a FlexEblock area. The data code block on which clock synchronization has beenperformed is allocated to and inserted into a FlexE calendar, and FlexE#A, A+1, . . . , N−1, and N are transmitted by using all sub-calendars.After two 66 B code blocks are separately inserted into transmissiondata of every two corresponding groups of instances, for example, FlexE#A and FlexE #A+1, the transmission data is interleaved and is outputvia a PHY of a 200 G PHY network.

De-mapping and de-multiplexing in the FlexE in OIF FlexE 2.0 arereversely performed relative to processes in FIG. 7 to FIG. 9, anddetails are not described herein again.

FIG. 10 is a schematic diagram of slot allocation in a FlexE groupincluding four physical interfaces. Each physical interface has 20sub-slots (sub-calendar), and therefore the FlexE group has 20×4sub-slots.

According to an OIF FlexE protocol standard, one FlexE group sends oneFlexE overhead code block to a remote PHY every 20×1023 code blocks oneach member PHY (1.0 standard) or instance (2.0). Eight FlexE overheadcode blocks that are sequentially sent from one overhead frame (FlexEoverhead frame), and thirty-two consecutive FlexE overhead frames formone multiframe (multiframe). The FlexE specifies that some fields of theoverhead frame carry a slot allocation table, and the slot table issynchronized to the remote PHY by using the FlexE overhead frame, toensure that both PHYs receive and send a FlexE client data flow by usinga same slot allocation table.

Based on the foregoing descriptions, the FlexE group includes a FlexEclient, a FlexE shim (FlexE Calendar), a PHY (OIF FlexE 1.0)/instance(OIF FlexE 2.0), and a link connection between PHYs. When a PHY faultoccurs in a FlexE group that carries FlexE client data, a faultindication code block is to be transmitted to notify a downstream deviceand an external device.

The following describes technical solutions in the embodiments of thepresent subject matter in detail with reference to the accompanyingdrawings. FIG. 11 is a flowchart of a method for indicating a faultaccording to an embodiment of the present subject matter. The method isapplied to FlexE, and specifically includes the following steps.

S111. Detect whether a fault occurs in at least one PHY included in aFlexE group.

A P node or a PE node in the FlexE network detects whether a PHY faultoccurs in a FlexE group that transmits a signal. In a specific example,the P node or the PE node in the FlexE network may detect, by using ansSLAI, whether a PHY fault occurs in the FlexE group that transmits asignal.

The sSLAI determines that a PHY fault occurs when detecting any one ofthe following: A PHY loses a signal (loss of signal, LOS), a PHY failsto lock a code block (loss of block lock), a PHY fails to lock analignment code block (loss of alignment marker lock), or a high biterror rate alarm signal is detected in a PHY

S112. When a fault occurs in the at least one PHY, periodically send afault indication code block to a FlexE client corresponding to the atleast one PHY in which the fault occurs.

The PHY herein may be a PHY in OIF FlexE 1.0, or may be a PHY or a FlexEinstance (FlexE Instance) corresponding to a PHY in OIF FlexE 2.0. TheFlexE client corresponding to the PHY in which the fault occurs is aFlexE client in a downstream direction of signal transmission by the PHYin which the fault occurs.

Herein, an example in which the sSLAI sends an SLAI code block as thefault indication code block is used for description.

In the foregoing method, when a PHY fault occurs, for example, the sSLAIperiodically sends an SLAI code block to the FlexE client correspondingto the at least one PHY that is carried on the FlexE group and in whichthe fault occurs. In the method, data transmission carried on anon-faulty channel of the same FlexE group is not affected, therebyreducing the number of affected FlexE clients. In addition, a pluralityof paths of different signals are transmitted on channels of the sameFlexE group without interfering with each other. Therefore, utilizationof a communications line may be improved, and a capability ofstatistical multiplexing is provided for a downstream transmission pathof an associated FlexE client channel of the same FlexE group in which afault occurs. Moreover, because transmission of a data flow on a FlexEclient channel carried by a non-faulty PHY in a FlexE group is notlimited, a possibility of a protection switchover mechanism between aplurality of PHYs in the FlexE group is provided, and a faultself-healing mechanism at a FlexE group level is allowed.

The periodically sending, by the sSLAI, an SLAI code block to a FlexEclient corresponding to the at least one PHY in which the fault occursincludes: sending an idle code block between such SLAI code blocks inadjacent periods. Alternatively, the sSLAI periodically sends an SLAIcode block to a FlexE client corresponding to the at least one PHY inwhich the fault occurs, where when the fault is detected, first, aplurality of SLAI code blocks are consecutively sent to the FlexE clientcorresponding to the at least one PHY in which the fault occurs, then anSLAI code block is periodically sent to the FlexE client correspondingto the at least one PHY in which the fault occurs, and an idle codeblock is sent between such SLAI code blocks in adjacent periods.

In an example, the SLAI code block is periodically sent. For example,one SLAI code block may be sent every 30000 idle code blocks, or 100SLAI code blocks may be sent every 30000 idle code blocks.Alternatively, the SLAI code block is periodically sent. For example,when a fault is detected in a PHY, 50 SLAI code blocks are sent first,then the SLAI code block is periodically sent, and an IIDLE code blockis sent between such SLAI code blocks in adjacent periods.

FIG. 12 is a schematic diagram of an idle code block according to anembodiment of the present subject matter. Idle code block: a type of64/66-bit block, where a synchronization header field is 10, a firstcontrol block byte is 0xIE, and subsequent eight consecutive seven bits(56 bits in total) are all 0x00.

Herein, the fault indication code block includes a control type fieldand a fault identification field which is used to indicate that a PHYfault occurs. Optionally, the fault indication code block may furtherinclude a fault type identification field, the fault type identificationfield is used to indicate a fault type of a fault occurring in the atleast one PHY, and the fault type includes: the PHY loses a signal, thePHY cannot lock a code block, the PHY cannot lock an alignment codeblock, and a high-bit error rate alarm is detected in the PHY Inaddition, the fault type is not limited to the foregoing content. Forexample, the fault type may alternatively be any one of the followingdetected in the PHY: an alarm indicating that a PCS is in a fault state(PCS_status=FALSE); a PHY (OIF FlexE 1.0)/instance (OIF FlexE 2.0) losesFlexE group frame lock or multiframe lock; PHY (OIF FlexE 1.0)/instance(OIF FlexE 2.0) mapping tables, PHY (1.0)/instance (2.0) numbers, orFlexE group numbers carried during frame lock or multiframe lock areinconsistent; or a receive clock skew between a plurality of PHYs (OIFFlexE 1.0)/instances (OIF FlexE 2.0) in a FlexE group is excessivelylarge and exceeds a range allowed by a chip. These are not listed one byone herein.

Optionally, the fault indication code block may be an SLAI code block.The SLAI code block is defined based on any reserved field specified inan IEEE 802.3 standard specification for a standard Ethernet.Specifically, FIG. 13 to FIG. 15 in the following show examples of anSLAI code block.

FIG. 13 is a schematic diagram of an example of an SLAI code blockaccording to an embodiment of the present subject matter. As shown inFIG. 13, the SLAI code block uses a control code block, where a controltype of the control code block is 0x4B, an O code is 0, D3 is 0 or anyvalue between 3 and 255, and others are 0.

FIG. 14 is a schematic diagram of another example of an SLAI code blockaccording to an embodiment of the present subject matter. As shown inFIG. 14, the SLAI code block uses a control code block, where a controltype of the control code block is 0x4B, an O code is a value that hasnot been standardized in a current IEEE 802.3 standard specification,for example, 10.

FIG. 15 is a schematic diagram of still another example of an SLAI codeblock according to an embodiment of the present subject matter. As shownin FIG. 15, the SLAI code block uses a control code block, where acontrol type of the control code block is 0x00, and each of D1 to D7takes any value.

When a PHY fault occurs, S111 may be performed to detect whether a faultin at least one PHY included in a FlexE group disappears. If the PHYfault in the does not disappear, perform S112 continues to be performed.

When the fault in the at least one PHY disappears, a fault indicationcode block is stopped from being sent to a FlexE client corresponding tothe at least one PHY in which the fault occurs.

Herein, when the fault in the PHY disappears, the SLAI code block isstopped from being periodically sent to the corresponding FlexE client,to notify a downstream device that the fault in the PHY disappears.

FIG. 16 is a flowchart of another method for indicating a fault in FlexEaccording to an embodiment of the present subject matter. The methodspecifically includes the following steps.

S161. Detect whether a FlexE client signal includes a fault indicationcode block.

In the FlexE network, a PE node located downstream detects a faultindication code block on a UNI side interface of the PE node. In aspecific example, in the FlexE network, a dSLAI of the PE node locateddownstream detects an SLAI code block on the UNI side interface of thePE node.

S162. When a predetermined fault indication code block is detected,continuously send a fault signal to a UNI corresponding to the FlexEclient signal.

Herein, the fault signal is a signal used to notify a UNI side useroutside the FlexE network that a fault occurs in the FlexE. When the UNIis a standard Ethernet interface, an LF signal is sent to the UNIaccording to an IEEE 802.3 standard specification. When the UNI is anSDH interface, an MS-AIS (multiplex section alarm indication signal)signal is sent to the UNI according to an ITU-T G.707 specification.When the UNI is an OTN interface, an ODU-AIS (optical data unit-alarmindication signal) signal is sent to the UNI according to an ITU-T G.709specification. When the UNI is a CPRI, and a CPRI synchronizationcontrol word is sent to a UNI side according to a CPRI standard, theCPRI synchronization control word is replaced with an invalid character,for example, K28.5 is replaced with 0 (where interfaces are CPRIs 1 to7), or /S/ is replaced with 0 (where interfaces are CPRIs 7A, and 8 to10), to trigger a downstream CPRI client to generate an LOF (loss offrame) alarm. Alternatively, the downstream CPRI client is triggered togenerate another alarm in another manner. There are also similar alarmsfor other user network interfaces, which are not listed herein one byone. The following uses a standard Ethernet interface as an example fordescription.

If detecting a predetermined fault indication code block, the dSLAIterminates the fault indication code block, and continuously sends an LFsignal to a corresponding UNI. The fault indication code block is thesame as that described above, and details are not described hereinagain. A format of the LF signal is shown in FIG. 17.

That a predetermined fault indication code block is detected means: onefault indication code block is detected, fault indication code blockswhose quantity is greater than a preset threshold are detected in apredetermined quantity of received code blocks, or fault indication codeblocks whose quantity is greater than a preset threshold are detectedwithin a predetermined time. In an example, if one SLAI code block isdetected in a process of receiving the FlexE client signal, it isdetermined that the predetermined SLAI code block is detected.Alternatively, if 30000 code blocks are consecutively received, fiveSLAI code blocks are detected, and a preset threshold is equal to 3, itis determined that the predetermined SLAI code block is detected. Inanother example, within a predetermined time, if five SLAI code blocksare detected, and a preset threshold is equal to 3, it is determinedthat the predetermined SLAI code block is detected.

After the predetermined fault indication code block is detected, thedSLAI of the PE node in the FlexE network continuously detects the SLAIcode block on the UNI side interface of the PE node. If no SLAI codeblock is detected anymore, the dSLAI stops sending the LF signal to theUNI. Furthermore, the exchange functions of a FlexE client and a UNIside user client may be quickly enabled, to restore data informationexchange.

That no SLAI code block is detected any more means: no SLAI code blockor SLAI code blocks whose quantity is less than a preset threshold aredetected in a predetermined quantity of received code blocks, or no SLAIcode block or SLAI code blocks whose quantity is less than a presetthreshold are detected within a predetermined time. In an example, afterthe predetermined SLAI is detected, if 30000 code blocks areconsecutively received, and no SLAI code block is detected, it isdetermined that no SLAI code block is detected anymore; or if two SLAIcode blocks are detected and a preset threshold is equal to 3, it isdetermined that no SLAI code block is detected anymore. In anotherexample, after the predetermined SLAI is detected, if no SLAI code blockis detected within, for example, 10 SLAI sending periods, it isdetermined that no SLAI code block is detected anymore; or if two SLAIcode blocks are detected within, for example, 10 SLAI sending periods,and a preset threshold is equal to 3, it is determined that no SLAI codeblock is detected anymore.

According to the method, the SLAI code block can be detected, and acapability, of the FlexE, of notifying a node outside the network that aPHY fault occurs in the network is retained.

The following describes the technical solutions of the present subjectmatter in detail with reference to specific embodiments. FIG. 18A toFIG. 18D are schematic diagrams of an example showing that a PHY faultoccurs according to an embodiment of the present subject matter.

As shown in FIG. 18A to FIG. 18D, a PE node PE1, a P node P1, a P nodeP2, and a PE node PE2 form a FlexE network. Two ends of the FlexEnetwork are connected to an Ethernet device CE1 and an Ethernet deviceCE2.

The Ethernet device CE1 transmits data with the Ethernet device CE2 byusing the PE node PE1, the P node P1, the P node P2, and the PE nodePE2.

The Ethernet device CE1 transmits user client service data #uc1 and userclient service data #uc2. The user client service data #uc1 and the userclient service data #uc2 are sequentially transmitted to the PE node PE1respectively through an upper layer, a medium access control (MAC)layer, and a physical layer.

In the PE node PE1, two paths of data are transmitted to the P node P1separately through a physical layer lower part (PHY lower part) and aphysical coding sublayer (PCS), through a layer-1.5 switching unit, andthrough a FlexE shim, a PCS, and a PHY lower part in a FlexE group #1.The layer-1.5 switching unit is layer 1.5, where the layer 1.5 is a datatransmission layer related to a FlexE protocol, and is located between aphysical layer and a MAC layer in an open system interconnection (OSI)seven-layer model.

In the P node P1, the two paths of data are transmitted to the P node P2separately through a PHY lower part, a PCS, and a FlexE shim in a FlexEgroup #1, through a layer-1.5 switching unit, and through a FlexE shim,a PCS, and a PHY lower part in a FlexE group #2.

In the P node P2, the two paths of data are transmitted to the PE nodePE2 separately through a PHY lower part, a PCS, and a FlexE shim in aFlexE group #2, through a layer-1.5 switching unit, and through a FlexEshim, a PCS, and a PHY lower part in a FlexE group #3.

In the PE node PE2, the two paths of data are transmitted to theEthernet device CE2 separately through a PHY lower part, a PCS, and aFlexE shim in a FlexE group #3, through the layer-1.5 switching unit,and through a PCS and a PHY lower part.

In the Ethernet device CE2, two paths of data are transmitted separatelyand sequentially through a PHY, a MAC, and an upper layer, to obtainuser client service data #uc3 and user client service data #uc4.Transmission of the user client service data #uc1 corresponds to thetransmission of the user client service data #uc3. Transmission of theuser client service data #uc2 corresponds to the transmission of userclient service data #uc4.

When a fault occurs in a receive-side physical layer link of a PHY #1port in the FlexE group #2 of the P node P2, a PHY #1 generates an LOSsignal. That is, a fault occurs in the PHY #1, leading to a fault in alllinks of an entire FlexE group #2.

Based on the OIF FlexE 1.0 specification, the P2 continuously sends anLF signal in a downstream direction of two FlexE clients, namely, aFlexE client #1 and a FlexE client #3, carried on the FlexE group #2,and an LF signal flow is transmitted through downstream paths of a FlexEclient #1 channel and a FlexE client #3 channel to the PE node PE2 and aFlexE client #2 and a FlexE client #5 carried on the FlexE group #3 ofthe P2 device.

FIG. 18A to FIG. 18D show that a fault occurs in a PHY between the FlexEgroup #2 of the P node P1 and the FlexE group #2 of the P node P2. Thefollowing describes the technical solutions of the embodiments of thepresent subject matter by using an example in which the foregoing PHYfault occurs.

In FIG. 19A to FIG. 22D, a P node performs data exchange from aneastbound FlexE client to a westbound FlexE client, and a PE nodeperforms data exchange between a FlexE client on an NNI side and a UNIside user client. An sSLAI of the P node is used to detect whether a PHYfault occurs. A dSLAI of the PE node is used to detect an SLAI codeblock, and the dSLAI may be deployed at a FlexE client on an NNI side ofthe PE node, or may be deployed on a UNI side of the PE node.

FIG. 19A to FIG. 19D are schematic diagrams of detecting a PHY faultaccording to an embodiment of the present subject matter. In FIG. 19B,when a PHY fault occurs on a link between the FlexE group #2 of the Pnode P1 and the FlexE group #2 of the P node P2, an LF signal is notcontinuously sent immediately to a downstream direction of the two FlexEclients (the FlexE client #1 and the FlexE client #3) carried on theFlexE group #2.

An sSLAI of the P node P2 periodically sends an SLAI code block to theFlexE client #1 carried on the FlexE group. FIG. 20A to FIG. 20D areschematic diagrams of sending an SLAI code block according to anembodiment of the present subject matter. In FIG. 20B, the sSLAI of theP node P2 periodically sends an SLAI code block. Optionally, an idlecode block is sent between such SLAI code blocks in two adjacentperiods.

In an example, the sSLAI may send two SLAI code blocks in one period,that is, two consecutive SLAI code blocks are sent at an interval of apredetermined time. An idle code block is sent between such SLAI codeblocks in two adjacent periods. A format of the idle code block is shownin FIG. 12, and the SLAI code block may be anyone shown in FIG. 13 toFIG. 15.

A dSLAI of the PE node PE2 detects a SLAI code block, terminates apredetermined SLAI code block when the SLAI code block is detected, andcontinuously sends an LF signal to the UNI. FIG. 21A to FIG. 21D areschematic diagrams of sending an LF signal according to an embodiment ofthe present subject matter. A format of the LF signal is shown in FIG.17.

When detecting the predetermined SLAI code block, the dSLAI terminatesthe SLAI code block, and continuously sends the LF signal to thecorresponding UNI, that is, interrupts the exchange functions of theFlexE client and UNI side user client, that is, interrupts originallyexchanged information.

It can be learned that, in this embodiment of the present subjectmatter, an LF signal is not continuously sent to a downstream directionof each FlexE client carried on a FlexE group immediately after a PHYfault is detected in the FlexE group. Instead, an SLAI code block isperiodically sent to a FlexE client #2 corresponding to a PHY #1 inwhich the fault occurs. The dSLAI of the PE node PE2 continuously sendsan LF signal to the UNI only after detecting the predetermined SLAI codeblock. That is, there is a condition for interrupting original exchangedinformation, and the condition is that the PE node PE2 locateddownstream detects the predetermined SLAI code block.

When the sSLAI of the P node P2 detects that the PHY fault in the FlexEgroup #2 disappears, the sSLAI of the P node P2 stops sending the SLAIcode block to the FlexE client #2 carried on the FlexE group. FIG. 22Ato FIG. 22D are schematic diagrams showing that a PHY fault disappearsaccording to an embodiment of the present subject matter.

The PE node PE2 does not detect the SLAI code block, that is, the SLAIcode block has disappeared, and stops continuously sending the LF signalto the related UNI. Refer to FIG. 22A to FIG. 22D.

The dSLAI of the PE node PE2 stops sending the LF signal to the UNI,that is, restores the exchange functions of the FlexE client on the NNIside and the UNI side user client, and no longer interferes withexchanged content.

The foregoing describes the method for indicating a fault in theembodiments of the present subject matter, and the following describesan apparatus for indicating a fault corresponding to the foregoingmethod.

FIG. 23 is a schematic structural diagram of an apparatus for indicatinga fault according to an embodiment of the present subject matter. Theapparatus corresponds to a method for indicating a fault.

The apparatus specifically includes a detection module 231 and a sendingmodule 232. It should be noted that an sSLAI/a dSLAI includes theapparatus in FIG. 23, that is, includes the detection module 231 and thesending module 232.

The detection module 231 is configured to detect whether a fault occursin at least one PHY included in a FlexE group.

The sending module 232 is configured to: when a fault occurs in the atleast one PHY, periodically send a fault indication code block to aFlexE client corresponding to the at least one PHY in which the faultoccurs.

In a possible implementation, that the sending module 232 isspecifically configured to: when a PHY fault occurs, periodically send afault indication code block to a FlexE client corresponding to the atleast one PHY in which the fault occurs includes: sending an idle codeblock between two adjacent fault indication code blocks.

In a possible implementation, the sending module 232 is specificallyconfigured to: when a PHY fault occurs, periodically send a faultindication code block to a FlexE client corresponding to the at leastone PHY in which the fault occurs, that is, when the fault is detected,consecutively send a plurality of fault indication code blocks to theFlexE client corresponding to the at least one PHY in which the faultoccurs, periodically send the fault indication code block to the FlexEclient corresponding to the at least one PHY in which the fault occurs,and send an idle code block between two adjacent fault indication codeblocks.

In a possible implementation, the fault indication code block includes acontrol type field and a fault identification field which is used toindicate that a fault occurs in a PHY

In a possible implementation, the fault indication code block furtherincludes a fault type identification field, the fault typeidentification field is used to indicate a fault type of the faultoccurred in the at least one PHY, and the fault type includes: the PHYloses a signal, the PHY cannot lock a code block, the PHY cannot lock analignment code block, and a high-bit error rate alarm is detected in thePHY

In a possible implementation, the fault indication code block is an SLAIcode block, and the SLAI code block is defined based on any fieldreserved in an IEEE 802.3 standard specification for a standardEthernet.

In a possible implementation, the detection module 231 is furtherconfigured to detect, when the fault occurs in the PHY, whether thefault in the at least one PHY included in the FlexE group disappears.

The sending module 232 is further configured to: when the fault in theat least one PHY disappears, stop sending the fault indication codeblock to the FlexE client corresponding to the at least one PHY in whichthe fault occurs.

FIG. 24 is a schematic structural diagram of an apparatus for indicatinga fault according to an embodiment of the present subject matter. Theapparatus corresponds to a method for indicating a fault.

The apparatus specifically includes a detection module 241 and a sendingmodule 242. It should be noted that a dSLAI includes the apparatus inFIG. 24, that is, includes the detection module 241 and the sendingmodule 242.

For example, in FlexE, a PE node receives a signal from a P node.

The detection module 241 is configured to detect whether a FlexE clientsignal includes a fault indication code block.

The sending module 242 is configured to: when a predetermined faultindication code block is detected, continuously send a fault signal to aUNI corresponding to the FlexE client signal.

Herein, the fault signal is a signal used to notify a UNI side useroutside the FlexE network that a fault occurs in the FlexE network. Whenthe UNI is a standard Ethernet interface, an LF (local fault) signal issent to the UNI according to an IEEE 802.3 standard specification. Whenthe UNI is an SDH interface, an MS-AIS (multiplex section alarmindication signal) signal is sent to the UNI according to an ITU-T G.707specification. When the UNI is an OTN interface, an ODU-AIS signal issent to the UNI according to an ITU-T G.709 specification. When the UNIis a CPRI interface, and a CPRI synchronization control word is sent tothe UNI side according to a CPRI standard, the CPRI synchronizationcontrol word is replaced with an invalid character, for example, K28.5is replaced with 0 (where interfaces are CPRIs 1 to 7), or /S/ isreplaced with 0 (where interfaces are CPRIs 7A and 8 to 10), to triggera downstream CPRI client to generate an LOF (loss of frame) alarm.Alternatively, the downstream CPRI client is. There are also similaralarms for other user network interfaces, which are not listed hereinone by one.

In a possible implementation, the detection module 241 is furtherconfigured to: after the predetermined fault indication code block isdetected, continuously detect the fault indication code block. Thesending module 242 is further configured to: when no fault indicationcode block is detected by the detection module, stop sending the faultsignal to the UNI.

According to the foregoing manner of the present subject matter, ifdetecting the predetermined fault indication code block, the dSLAIterminates the fault indication code block, and continuously sends an LFsignal to the corresponding UNI. The fault indication code block is thesame as that described above, and details are not described hereinagain.

In a possible implementation, that a predetermined fault indication codeblock is detected means that one fault indication code block isdetected, fault indication code blocks whose quantity is greater than apreset threshold are detected in a predetermined quantity of receivedcode blocks, or fault indication code blocks whose quantity is greaterthan a preset threshold are detected within a predetermined time. Thatno fault indication code block is detected means that no faultindication code block or fault indication code blocks whose quantity isless than the preset threshold are detected in the predeterminedquantity of received code blocks, or no fault indication code block orfault indication code blocks whose quantity is less than the presetthreshold are detected within the predetermined time.

In a possible implementation, the fault signal is any one of an LFsignal, an MS-AIS signal, an ODU-AIS signal, a CPRI invalidsynchronization control word signal, or another signal.

In the method, the fault indication code block may be detected, and acapability, of the FlexE, of notifying a node outside the network that aPHY fault occurs in the network is retained.

FIG. 25 is a schematic block diagram of a fault indication deviceaccording to an embodiment of the present subject matter. As shown inFIG. 25, the fault indication device 2500 includes an input device 2501,an input interface 2502, a processor 2503, a memory 2504, an outputinterface 2505, and an output device 2506.

The input interface 2502, the processor 2503, the memory 2504, and theoutput interface 2505 are connected to each other by using a bus 2510.The input device 2501 and the output device 2506 are connected to thebus 2510 respectively by using the input interface 2502 and the outputinterface 2505, and are further connected to another component of thefault indication device 2500.

Specifically, the input device 2501 receives external input information,and transmits the input information to the processor 2503 through theinput interface 2502. The processor 2503 processes the input informationaccording to a computer-executable instruction stored in the memory2504, to generate output information, temporarily or permanently storesthe output information in the memory 2504, and transmits the outputinformation to the output device 2506 through the output interface 2505.The output device 2506 outputs the output information to the outside ofthe fault indication device 2500 for use by a user.

The fault indication device 2500 may perform the steps in theembodiments of the present subject matter.

The processor 2503 may be one or more central processing units (CPU(s)).When the processor 2503 is one CPU, the CPU may be a single-core CPU ora multi-core CPU.

The memory 2504 may be, but not limited to, one or more of arandom-access memory (RAM), a read-only memory (ROM), an erasableprogrammable read-only memory (EPROM), a compact disc read-only memory(CD-ROM), a hard disk, and the like. The memory 2504 is configured tostore program code.

It may be understood that, in this embodiment of the present subjectmatter, the fault indication device 2500 in FIG. 25 may be the apparatusin FIG. 23, and the fault indication device 2500 may implement afunction of each module in FIG. 23.

In addition, it may be understood that, in this embodiment of thepresent subject matter, the fault indication device 2500 in FIG. 25 maybe the apparatus in FIG. 24, and the fault indication device 2500 mayimplement a function of each module in FIG. 24.

In addition, an embodiment of the present subject matter provides anetwork device, including the apparatuses in FIG. 23 and FIG. 24. Theapparatus shown in FIG. 23 may be disposed on a network-to-networkinterface chip of the device, and the apparatus shown in FIG. 24 may bedisposed on a user-network interface chip of the device.

In addition, an embodiment of the present subject matter furtherprovides a network device, including the apparatus in FIG. 23. Theapparatus shown in FIG. 23 may be disposed on a network-to-networkinterface chip of the device.

All or some of the foregoing embodiments may be implemented by usingsoftware, hardware, firmware, or any combination thereof. When all orsome of the foregoing embodiments are implemented in a form of acomputer program product, the computer program product includes one ormore computer instructions. When the computer program instructions areloaded or executed in a computer, the procedures or functions accordingto the embodiments of the present subject matter are completely orpartially generated. The computer may be a general-purpose computer, adedicated computer, a computer network, or other programmableapparatuses. The computer instructions may be stored in acomputer-readable storage medium or may be transmitted from acomputer-readable storage medium to another computer-readable storagemedium. For example, the computer instructions may be transmitted from awebsite, computer, server, or data center to another website, computer,server, or data center in a wired (for example, a coaxial cable, anoptical fiber, or a digital subscriber line (DSL)) or wireless (forexample, infrared, radio, or microwave) manner. The computer-readablestorage medium may be any usable medium accessible by a computer, or adata storage device, such as a server or a data center, integrating oneor more usable media. The usable medium may be a magnetic medium (forexample, a floppy disk, a hard disk, or a magnetic tape), an opticalmedium (for example, a digital video disk (DVD)), or a semiconductormedium (for example, a solid-state drive (SSD)), or the like.

Each part of this specification is described in a progressive manner,for same or similar parts in the embodiments, refer to theseembodiments, and each embodiment focuses on a difference from otherembodiments. Especially, apparatus and system embodiments are basicallysimilar to method embodiments, and therefore are described briefly. Forrelated parts, refer to descriptions on the method embodiments.

What is claimed is:
 1. A method comprising: detecting whether a faultoccurs in at least one physical layer entity included in a flexibleEthernet group; and when a fault occurs in the at least one physicallayer entity, periodically sending a fault indication code block to aflexible Ethernet client corresponding to the at least one physicallayer entity in which the fault occurs, wherein the periodically sendingthe fault indication code block to the flexible Ethernet clientcorresponding to the at least one physical layer entity in which thefault occurs comprises: sending an idle code block between the faultindication code blocks in adjacent periods.
 2. A method comprising:detecting whether a fault occurs in at least one physical layer entityincluded in a flexible Ethernet group; and when a fault occurs in the atleast one physical layer entity, periodically sending a fault indicationcode block to a flexible Ethernet client corresponding to the at leastone physical layer entity in which the fault occurs, wherein theperiodically sending the fault indication code block to the flexibleEthernet client corresponding to the at least one physical layer entityin which the fault occurs comprises: when the fault is detected,consecutively sending at least two of the fault indication code blocksto the flexible Ethernet client corresponding to the at least onephysical layer entity in which the fault occurs, periodically sendingthe fault indication code block to the flexible Ethernet clientcorresponding to the at least one physical layer entity in which thefault occurs, and sending an idle code block between the faultindication code blocks in adjacent periods.
 3. The method according toclaim 1, wherein the fault indication code block comprises a controltype field and a fault identification field which is used to indicate anoccurrence of the fault in the at least one physical layer entity. 4.The method according to claim 3, wherein the fault indication code blockfurther comprises a fault type identification field, the fault typeidentification field is used to indicate a fault type of the faultoccurred in the at least one physical layer entity, and wherein thefault type comprises: the physical layer entity loses a signal; thephysical layer entity cannot lock a code block; the physical layerentity cannot lock an alignment code block; and a high bit error ratealarm is detected in the physical layer entity.
 5. The method accordingto claim 1, wherein the fault indication code block is a service layeralarm indication code block, and the service layer alarm indication codeblock is defined based on a field reserved in an IEEE 802.3 standardspecification for a standard Ethernet.
 6. The method according to claim1, wherein the method further comprises: detecting whether the fault inthe at least one physical layer entity included in the flexible Ethernetgroup disappears; and when the fault in the at least one physical layerentity disappears, stopping sending the fault indication code block tothe flexible Ethernet client corresponding to the at least one physicallayer entity in which the fault occurs.
 7. A method comprising:detecting whether a flexible Ethernet client signal comprises a faultindication code block; when a predetermined fault indication code blockis detected, continuously sending a fault signal to a user-networkinterface corresponding to the flexible Ethernet client signal, afterthe predetermined fault indication code block is detected, continuouslydetecting the fault indication code block; and when no fault indicationcode block is detected, stopping sending the fault signal to theuser-network interface, wherein the fault indication code blockcomprises a control type field and a fault identification field which isused to indicate an occurrence of a fault in at least one physical layerentity.
 8. The method according to claim 7, wherein the fault indicationcode block further comprises a fault type identification field, thefault type identification field is used to indicate a fault type of thefault occurred in the at least one physical layer entity, and whereinthe fault type comprises: the physical layer entity loses a signal; thephysical layer entity cannot lock a code block; the physical layerentity cannot lock an alignment code block; and a high bit error ratealarm is detected in the physical layer entity.
 9. The method accordingto claim 7, wherein the fault indication code block is a service layeralarm indication code block, and the service layer alarm indication codeblock is defined based on a field reserved in an IEEE 802.3 standardspecification for a standard Ethernet.
 10. A method comprising:detecting whether a flexible Ethernet client signal comprises a faultindication code block; and when a predetermined fault indication codeblock is detected, continuously sending a fault signal to a user-networkinterface corresponding to the flexible Ethernet client signal, whereinthat a predetermined fault indication code block is detected indicatesthat: one fault indication code block is detected; fault indication codeblocks whose quantity is greater than a preset threshold are detected ina predetermined quantity of received code blocks; or fault indicationcode blocks whose quantity is greater than a preset threshold aredetected within a predetermined time, and wherein that no faultindication code block is detected indicates that: no fault indicationcode block or fault indication code blocks whose quantity is less thanthe preset threshold are detected in the predetermined quantity ofreceived code blocks; or no fault indication code block or faultindication code blocks whose quantity is less than the preset thresholdare detected within the predetermined time.
 11. A method comprising:detecting whether a flexible Ethernet client signal comprises a faultindication code block; when a predetermined fault indication code blockis detected, continuously sending a fault signal to a user-networkinterface corresponding to the flexible Ethernet client signal, whereinthe fault signal is one of a local fault signal, a multiplex sectionalarm indication signal, an optical data unit alarm indication signal,and a common public radio frequency interface-invalid synchronizationcontrol word signal.
 12. An apparatus comprising a processor, whereinthe processor is configured to: detect whether a fault occurs in atleast one physical layer entity included in a flexible Ethernet group;and when a fault occurs in the at least one physical layer entity,periodically send a fault indication code block to a flexible Ethernetclient corresponding to the at least one physical layer entity in whichthe fault occurs, wherein the periodically sending the fault indicationcode block to the flexible Ethernet client corresponding to the at leastone physical layer entity in which the fault occurs comprises: sendingan idle code block between the fault indication code blocks in adjacentperiods.
 13. An apparatus comprising a processor, wherein the processoris configured to: detect whether a fault occurs in at least one physicallayer entity included in a flexible Ethernet group; and when a faultoccurs in the at least one physical layer entity, periodically send afault indication code block to a flexible Ethernet client correspondingto the at least one physical layer entity in which the fault occurs,wherein the periodically sending the fault indication code block to theflexible Ethernet client corresponding to the at least one physicallayer entity in which the fault occurs comprises: when the fault isdetected, consecutively sending at least two of the fault indicationcode blocks to the flexible Ethernet client corresponding to the atleast one physical layer entity in which the fault occurs, periodicallysending the fault indication code block to the flexible Ethernet clientcorresponding to the at least one physical layer entity in which thefault occurs, and sending an idle code block between two adjacent faultindication code blocks of the fault indication code blocks.
 14. Theapparatus according to claim 12, wherein the fault indication code blockcomprises a control type field and a fault identification field which isused to indicate an occurrence of the fault occurs in the at least onephysical layer entity.
 15. The apparatus according to claim 14, whereinthe fault indication code block further comprises a fault typeidentification field, the fault type identification field is used toindicate a fault type of the fault occurred in the at least one physicallayer entity, and wherein the fault type comprises: the physical layerentity loses a signal; the physical layer entity cannot lock a codeblock; the physical layer entity cannot lock an alignment code block;and a high bit error rate alarm is detected in the physical layerentity.
 16. The apparatus according to claim 12, wherein the faultindication code block is a service layer alarm indication code block,and the service layer alarm indication code block is defined based on afield reserved in an IEEE 802.3 standard specification for a standardEthernet.